After doing the tutorial I understood the overall goal of the game. But I understood only at the next level that each character has a specific role, which I liked. I understood better what you were trying to show in the tutorial in the first place. The art is cute too.
Sometimes sending a character from one place to another is a bit difficult, maybe due to the collisions sizes. I would increase the sizes of the openings (doors), as well as the size of the are where the crystals are activated, to make it easier.
Good job overall :)